Just because I think a 51 should get 150 because it had it in real life doesn't mean I dont know how to fly. Ive been flying for about a decade in various sims. I fly the current plane just fine thank you, and I find it most effective. Once again, I see that when we dont have any real arguments we resort to assuming motive or incompetence on the part of the OP.
I'm not sure how you define real arguments. You claim that 150 Octane fuel was "standard" in the 8th AF. When? Show me the modified Mustang data blocks where they changed the octane number from the standard 100/130.
This is the 'standard' 51 Data Block.

This 'standard' data block is on a 479th FG P51D in the late Fall of 44. I don't see any mention of 150 Octane on it.

Here's the restored Combat Vet P51D "Twilight Tear', one of the most accurate of the 51 restorations out there. Not the 100/130 on the data block. 78th had their 51s late in 44 and into 45.

This one is on a 352nd FG 51
inverted the colors so the numbers would show better. 100/130

So was 150 octane used? Yep. It was helpful in the Spits and Mustangs chasing V-1s. Was it standard for the 8th? 100/130 octane was standard. Did they use 100/150? In some instances yes, but I wouldn't call it standard.